2020, October 7-8: One Night, Four Planets

During early October nights four bright planets and the moon appear in the sky.  Jupiter, Saturn, and Mars shine during evening hours.  Before sunrise brilliant Morning Star Venus and Mars gleam in the sky.

by Jeffrey L. Hunt

During early October nights, Jupiter, Saturn, and Mars shine during the early evening hours.  By morning, Mars is in the western sky as Venus sparkles in the east.  The moon is moving toward Venus for a grouping as mid-month approaches on the calendar.

Jupiter and Saturn shine from the southern sky as the sky darkens. Both planets are gently moving eastward compared to the starry background in eastern Sagittarius.  They are about 7° apart.

Jupiter catches Saturn on December 21, 2020, in what is called a Great Conjunction.  Both planets are slow-moving.  Jupiter revolves around the sun in nearly 12 years, while Saturn takes nearly 30 years to make one solar circuit.

Jupiter and Saturn group together nearly every 20 years.  This is the closest conjunction since 1623.

This is an event in slow motion as Jupiter inches toward the Ringed Wonder.  With a binocular make regular observations to watch the shrinking gap

Jupiter sets in the southwestern sky before midnight and Saturn follows about 40 minutes later.

The Sagittarius region near Saturn has a kite-shape group made of four dim stars.  Use a binocular to locate it.  It is known informally as the Territory of Dogs or Dogs Kingdom.

Mars – a few days after its closest approach to Earth – is nearing its opposition (October 13).  While at its brightest, Earth passes between the sun and Mars.  The sun and Mars are on opposite each other in the sky.

Mars rises in the east when the sun sets in the west, appears in the south near midnight, and sets in the west.

This image shows the Red Planet compared to its starry background during the early evening.  On the photo Mars is near Mu Piscium (μ Psc).  During the next few weeks watch the planet move toward 80 Piscium (80 Psc).

Mars is retrograding compared to the stars. This an illusion from Earth passing an outer planet.  Mars continues to retrograde for the next month.

In the morning Mars is in the west.  In the photo above, notice how the orientation of the stars appears shifted from the evening view.  The relationship of the stars is the same as during the evening photo.

As morning twilight begins look eastward for brilliant Venus.  It is stepping eastward in front of the stars of Leo.  In the photo above it appears near Rho Leonis (ρ Leo on the photo).

See our summary about Venus during October 2020 and the feature article  about Venus as a Morning Star.

Meanwhile, the moon appears farther eastward each morning.  In the photo above, the gibbous moon was seemingly between the Bull’s Horns, Elnath and Zeta Tauri (ζ Tau on the photo).

Each morning look at Venus and the nearby starfield with a binocular as the planet steps farther away from Regulus and moves away from ρ Leo.

Watch Venus continue to move through Leo during most of October.

The moon is in the region with Venus and Regulus beginning October 12.

Read more about the planets during October.